Aspects of the subject disclosure include a pressure-sensing device consisting of a housing including a membrane and one or more piezoresistive elements disposed on the membrane to sense a displacement due to a deflection of the membrane. A first set of electrodes is disposed over the membrane, and a second set of electrodes is disposed on a permeable port of the device at a distance from the membrane. The first and second sets of electrodes form an electrostatic actuator to exert a repulsive force onto the membrane to reduce the deflection of the membrane.

Provided is a measurement method including measuring, by using a piezoelectric sheet sensor in contact with a measurement object, vibration transmitted from the measurement object to the piezoelectric sheet sensor and measuring pressing force between the measurement object and the piezoelectric sheet sensor.

The present disclosure relates to piezoelectric detection circuits, methods and display devices. A piezoelectric detection circuit is provided that may comprise: a piezoelectric device to convert a pressure into a direct current (DC) signal and to convert a sound wave into an alternating current (AC) signal; a comparison circuit configured to output the direct current signal to a signal processor in a case where the piezoelectric device outputs DC signal, and to output the alternating current signal to the mixer in a case where the piezoelectric device outputs AC signal; the mixer configured to perform a mixing process on the AC signal to generate a mixed signal; and the signal processor configured to process the mixed signal output from the mixer or the direct current signal output from the comparison circuit, to detect the pressure or the sound.

A stress estimation method for a machine structure according to an embodiment is provided with a calculation step of calculating a relationship between the stress generated at the evaluation target position and a physical quantity including a sound pressure or vibration generated at a detection position different from the evaluation target position during vibration of the machine structure. The stress estimation method for a machine structure is provided with a detection step of detecting the physical quantity generated at the detection position during operation of the machine structure. The stress estimation method for a machine structure is provided with an estimation step of estimating the stress generated at the evaluation target position during operation of the machine structure on the basis of the relationship calculated in the calculation step and the physical quantity detected in the detection step.

Embodiments of the present invention provide an apparatus including a micromirror, an excitation structure containing or supporting the micromirror, and at least one piezoelectric sensor. The excitation structure includes at least one piezoelectric actuator, the excitation structure being configured to resonantly excite the micromirror so as to cause a deflection of the micromirror. The at least one piezoelectric sensor is configured to provide a sensor signal dependent on the deflection of the micromirror, the piezoelectric sensor being connected to the excitation structure so that during the resonant excitation of the micromirror, the sensor signal and the deflection of the micromirror exhibit a fixed mutual phase relationship.

A multi-axis piezoelectric stress-sensing device, a multi-axis piezoelectric stress-sensing device polarization method, and a piezoelectric sensing detection system thereof are disclosed. The piezoelectric sensing detection system is used for a machining tool. The multi-axis piezoelectric stress-sensing device includes a piezoelectric sensing film, a first electrode, a second electrode, a third electrode, and a fourth electrode. The piezoelectric sensing film has four corners. The first electrode, the second electrode, the third electrode and the fourth electrode are located at the four corners of the piezoelectric sensing film, and at least one electrode is used to polarize another electrode according to at least one polarization direction.

Structural health monitoring (SHM) methods, apparatus and techniques involve building deformation fields maps (amplitude and phase related to excitation) on the surface of the structural component under monitoring based on a network of strain measurements by fiber Bragg grating sensors.

A force detection sensor includes a base member having a first surface subjected to an external force and a second surface having a normal direction different from the first surface, and electrode fingers placed on the second surface, wherein an arrangement direction of the electrode fingers is different from the normal direction of the first surface in a plan view of the second surface. Further, the second surface includes a surface of a piezoelectric material. A constituent material of the piezoelectric material is quartz crystal. The first surface crosses an electrical axis of the quartz crystal.

A piezoelectric element device includes: a substrate including a plurality of vibrating portions having a first vibrating portion and a second vibrating portion; a piezoelectric element group in which a plurality of piezoelectric elements having a first piezoelectric element and a second piezoelectric element provided in the plurality of vibrating portions are coupled in parallel to each other; a plurality of load detectors having a first load detector including the first vibrating portion and the first piezoelectric element provided in the first vibrating portion and a second load detector including the second vibrating portion and the second piezoelectric element provided in the second vibrating portion; and a resin layer covering the piezoelectric element group. The first load detector resonates at a first resonance frequency, the second load detector resonates at a second resonance frequency, the first resonance frequency and the second resonance frequency are different from each other, the first resonance frequency changes in accordance with a load applied to the first load detectors via the resin layer, the second resonance frequency changes in accordance with a load applied to the second load detectors via the resin layer, and a first resonance frequency change range, which are changeable range of the first resonance frequency, and a second resonance frequency change range, which are changeable range of the second resonance frequency, do not overlap each other.

A multi-axis piezoelectric stress-sensing device, a multi-axis piezoelectric stress-sensing device polarization method, and a piezoelectric sensing detection system thereof are disclosed. The piezoelectric sensing detection system is used for a machining tool. The multi-axis piezoelectric stress-sensing device includes a piezoelectric sensing film, a first electrode, a second electrode, a third electrode, and a fourth electrode. The piezoelectric sensing film has four corners. The first electrode, the second electrode, the third electrode and the fourth electrode are located at the four corners of the piezoelectric sensing film, and at least one electrode is used to polarize another electrode according to at least one polarization direction.